Process for the dyeing of polyester fibre materials



United States Patent 3,699,513 PRGCESS FGR THE DYETNG 0F POLYESTER FTBRE MATERIALS Giinter Gehrlte, Cologne-Flittard, Germany, assignor to Farhenfahrilten Bayer Aktiengesellschaft, Leverlsusen, Germany, a corporation of Germany No Drawing. Filed Nov. 1, 1960, Ser. No. 66,420 4 Claims. (Cl. 8-39) This invention relates to the dyeing of fibre materials consisting essentially of polyesters and to a dyestufi especially suited therefor.

It has been found that synthetic fibre materials consisting essentially of linear polyesters can be dyed with 1,4-diamino-2-nitroanthraquinone.

The dyeing can be effected by those methods which are usually employed for the dyeing of polyester fibre materials. Thus for example the dyeing can be effected at the temperature of boiling advantageously in the presence of the carriers normally employed, such as benzoic acid, salicyclic acid, cresotic acid methyl ester, 0- or p-hydroxydiphenyl or trichloro'benzene; the dyeing can, however, also be carried out at elevated temperature under pressure.

The dyestuif is advantageously used in a finely divided state. This condition of fine dispersion can be achieved e.g. by dissolving in sulphuric acid and pouring the solution onto ice and by grinding with dispersing agents.

It is surprising that the colourings effected with the dyestuif useable according to the invention show very good fastness properties and in particular a very good fastness to light.

Example 1 1 kg. of polyester fibers, for example polyethylene glycol terephthalate, a linear polyester, is dyed for two hours at 125 C. under pressure in a bath liquor consisting of 20-40 litres of water with a suspension of 10 g. of 1,4-

Patented July 30, 1953 "ice 2 diamino-2-nitro-anthraquinone which has preferably been converted beforehand to a very finely divided state, for example dissolving in sulphuric acid and pouring the solution onto ice or by grinding with dispersing agents. A

strong blue green colouration of very good fastness is obtained. If the dyeing is carried out at 95-1 00 C. an if the dye bath has a carrier added thereto, for example 50 0 g. of benzoic acid or 100 g. of 0- or p-hydroxydiphenyl or 100 g. of trichlorobenzene or 100 g. of cresoctic acid methyl ester, if necessary in the form of emulsion, similar dyeings are obtained.

We claim:

1. In the process for dyeing linear polyester fibre materials, the improvement which comprises applying thereto as dyestufi 1,4-diamino-2-nitroanthraquinone.

2. A product obtained by the process of claim 1.

3. The process of claim 1 wherein the polyester material is polyethylene glycol terephthalate.

4. A process for dyeing polyethylene glycol terephthalate which comprises boiling the fibers in the presence of a member selected from the group consisting of ben- Zoic acid, salicyclic acid, cresotic acid methyl ester, o-hydroxydiphenyl, p-hydr-oxydiphenyl and trichlorobenzene with 1,4-diamino-2-nitroanthraquinone.

References Cited in the file of this patent UNITED STATES PATENTS 2,757,064- Speck July 31, 1956 2,918,344 Jenny Dec. 22, 1959' FOREIGN PATENTS 548,539 Belgium June 30, 1956 OTHER REFERENCES Venkataraman: Synthetic Dyes, vol. 1, Academic Press Inc., Publishers, New York, page 323. 

1. IN THE PROCESS FOR DYEING LINEAR POLYESTER FIBRE MATERIALS, THE IMPROVEMENT WHICH COMPRISES APPLYING THERETO AS DVESTUFF 1.4-DIAMINO-2-NITROANTHRAQUINONE. 